package cc.openhome;

import java.util.*;

public class Average2 {
    public static void main(String[] args) {	
	try {
	    Scanner console = new Scanner(System.in);
	    double sum = 0;
	    int count = 0;
	    while (true) {
		int number = console.nextInt();
		if (number == 0) {
		    break;
		}
		sum += number;
		count++;
	    }
	    System.out.printf("平均 %.3f%n", sum / count);
	} catch (InputMismatchException ex) {
		System.out.println("必须输入整数");
	}
    }
}
